With the process according to the invention there is obtained the production of compacted blocks starting from any material (marble, stone and other materials of various kinds) and a binder in the most suitable proportions, intended to be cut into slabs or into blocks of smaller dimensions for employment in building construction.
The current state of the art can be summarised in the Italian Patent No. 82540/A/75 filed by the same applicant on 5th Sept. 1975 and improved in the first addition No. 85564/A/77 filed 22nd Apr. 1977 and in the patent No. 85558/A/81 filed by the same applicant on 7th May 1981.
In the first patent recited above and in the improvement described in the first addition there is set forth a process with combined action of vibration and pressure in an ambiance deprived of air for the formation of granulates of stone material bound with resin.
Said process requires the use of fragmented stone material controlled within a restricted range (max. 4 mm.), a combined action of vibration and pressure in an ambiance deprived of air in order to obtain a condensing of the material itself and subsequently a catalysis by heat of the resin by suitable provided means.
In the third patent mentioned above, there are obtained blocks of considerable dimensions (as large as 305.times.125.times.80 cm) using granules of marble of particle size as large as 200 mm. The material of controlled particle size is deposited, in the presence of air, in a mould together with the binder mixture coming from a suitable mixing machine. The mould filled in this manner is introduced into a moulding machine wherein there is complete de-aeration and compacting of the materials under vibration, until there is complete formation of the block. The block made in this manner is usually left to rest in a natural ambiance, or is introduced into ovens for the catalysis by heat of the resin.
These two processes have some inconveniences and in particular:
(1) the first one, with its improvement, requiring very small particles ( max.4 mm) needs a process of fragmentation and sieving of the stone material, thereby increasing the time for preparation. As the granules are very small there is required a large quantity of binder because the ratio of volume to surface area is small and thus the total area to be covered is very large.
(2) the second one, eliminating the inconveniences of the first one, does not present any others of great importance. The mixing and the compacting in the mould take place in open air, thereby favouring the formation of voids in the material which are difficult to diliminate solely by vibration in an ambiance deprived of air.
With the present invention it is sought to eliminate the above-mentioned inconveniences and there is therefore proposed a plant capable of producing blocks of considerable dimensions (up to 305.times.125.times.80 cm) using any materials of particle size up to 200 mm. together with powders and granules of the said materials.